Navigation Links
Caffeine's effect on the brain's adenosine receptors visualized for the first time

Reston, Va. (November 1, 2012) Molecular imaging with positron emission tomography (PET) has enabled scientists for the first time to visualize binding sites of caffeine in the living human brain to explore possible positive and negative effects of caffeine consumption. According to research published in the November issue of The Journal of Nuclear Medicine, PET imaging with F-18-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (F-18-CPFPX) shows that repeated intake of caffeinated beverages throughout a day results in up to 50 percent occupancy of the brain's A1 adenosine receptors.

"The effects of caffeine to the human body are generally attributed to the cerebral adenosine receptors. In the human brain the A1 adenosine receptor is the most abundant," said David Elmenhorst, MD, lead author of "Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with F-18-CPFPX and PET." "In vitro studies have shown that commonly consumed quantities of caffeine have led to a high A1 adenosine occupancy. Our study aimed to measure the A1 adenosine receptor occupancy with in vivo imaging."

Fifteen male volunteers participated in the study. They abstained from caffeine intake for 36 hours and then underwent a PET scan with F-18-CPFPX. Caffeine was then introduced in short intravenous infusions, increasing in amount. To estimate the occupancy of A1 adenosine receptors by caffeine, the distribution volume at the baseline period of the PET scan was compared with the distribution volume after caffeine administration. Researchers determined that the concentration of the caffeine that displaces 50 percent of the binding of F-18-CPFPX to the A1 adenosine receptor was 13 mg/L, or approximately four to five cups of coffee.

An important finding of the study is that in most regular coffee drinkers about half of the A1 adenosine receptors may be occupied by caffeine. It is likely that this blockage of a substantial amount of cerebral A1 adenosine receptors will result in adaptive changes and lead to chronic alterations of receptor express and availability.

"There is substantial evidence that caffeine is protective against neurodegenerative diseases like Parkinson's or Alzheimer's disease," noted Elmenhorst. "Several investigations show that moderate coffee consumption of 3 to 5 cups per day at mid-life is linked to a reduced risk of dementia in late life. The present study provides evidence that typical caffeine doses result in a high A1 adenosine receptor occupancy and supports the view that the A1 adenosine receptor deserves broader attention in the context of neurodegenerative disorders."

Caffeine is the most commonly consumed psychoactive substance worldwide and an active ingredient in innumerable food and beverages. Eighty percent of U.S. adults consume caffeine every day; the average for adults is 200 mg of caffeine per day (two 5-ounce cups of coffee or four sodas). It affects an individual's alertness, attention, cognitive performance, as well as reduces sleepiness.


Contact: Susan Martonik
Society of Nuclear Medicine

Related medicine news :

1. New MS drug proves effective where others have failed
2. New study shows effects of prehistoric nocturnal life on mammalian vision
3. Health inequalities could be reduced by more effective health care, says new study
4. Health inequalities could be reduced by more effective healthcare, says new study
5. Genes May Determine Aspirins Effect on Advanced Colon Cancer
6. As painkiller overdoses mount, researchers outline effective approaches to curb epidemic
7. Is magnetic therapy effective for tinnitus?
8. Considerably more patients may benefit from effective antidiabetic drug
9. Surgery more profound effect than anesthesia on brain pathology, cognition in Alzheimers mice
10. NIH-funded analysis estimates effective PrEP dosing
11. Effects of stopping alcohol consumption on subsequent risk of esophageal cancer
Post Your Comments:
(Date:10/13/2015)... CA (PRWEB) , ... October 13, 2015 , ... Dr. ... by Medical New Today on September 18, 2015. The research, which was conducted at ... Dr. Wael Sabbah and colleagues, show connections between stress during pregnancy and future dental ...
(Date:10/13/2015)... , ... October 13, 2015 , ... A child without ... why SmileCareClub , the leading remote invisible aligner system, has joined with ... otherwise go without it. For each aligner treatment plan purchased, SmileCareClub will donate one ...
(Date:10/13/2015)... ... October 13, 2015 , ... ... today their Title Sponsorship of Synergy 2015. The annual WennSoft KEY2ACT user conference ... Valley Ranch and will unite customers, partners, WennSoft team members and sponsors to ...
(Date:10/13/2015)... ... October 13, 2015 , ... T-System and Centegra Health ... 59,000 emergency department visits per year, today announced the successful and rapid deployment ... clinical, operational and financial outcomes. , In less than four days, ...
(Date:10/13/2015)... CA (PRWEB) , ... October 13, 2015 , ... ... of the university’s new School of Nursing. Dr. McLeod—who earned her Doctor of ... in nursing and education that has spanned four decades. , Dr. McLeod’s long ...
Breaking Medicine News(10 mins):
(Date:10/13/2015)... Oct. 13, 2015   Happy Vitals ... laboratory home testing kit for breast milk.  ... provide an unparalleled, detailed assessment of the ... proteins, carbs and key vitamins—all charted over ... personal health tracking.  In addition, Happy Vitals also ...
(Date:10/13/2015)... Calif. , Oct. 13, 2015   Rosa ... advisory firm in Quantitative Systems Pharmacology (QSP)/ PhysioPD™ , ... Engineer, will lead a workshop at the QSP ... in Boston, MA.  The conference ... pharmaceutical drug development.  Dr. Friedrich,s workshop is entitled "Using ...
(Date:10/13/2015)... -- World Thrombosis Day Interactive Infographic   ... --> World Thrombosis Day Interactive Infographic ... vital global awareness of thrombosis, its causes, risk ... formation of potentially deadly blood clots in the ... (VTE) - or the artery (arterial thrombosis) [1]  - ...
Breaking Medicine Technology: